Fitting brake pipes
If a brake pipe has become corroded to the extent that it’s breaking down, it will not only fail the MoT test, but is also at risk of leaking brake fluid, so it’s worthwhile renewing either a section of it, or the entire length.
If you need to undo a brake pipe at a connection (e.g. a pipe nut), it’s often easier to cut the pipe close to the nut, crush the end to prevent fluid loss, then use a ring spanner or socket to undo it, which provides more grip than an open ended spanner.
After cutting through a brake pipe, brake fluid will leak out. Crushing the ends of the pipework will stop the leak, but you can also press the brake pedal down and wedge a length of wood against it.
When removing an old length of brake pipe that you intend to replace, use it as a template for the new pipe, so try to retain its shape and length. Remember where the pipe is clipped into position and make sure these fixings are in good condition.
With the old brake pipe removed, measure its length with a piece of string, then make up the same length with new pipework. Add suitable pipe nut connections and flare the ends using a flaring tool (see the separate information on flaring tools).
Carefully feed the new brake pipe into position on the underside of the vehicle. Try to manoeuvre it into position and line it up with any clips or other methods of securing it to the vehicle.
If you need to make a bend in the brake pipe, use something round, such as a large socket, to avoid kinking the pipe. If you kink the pipe, this could restrict brake fluid, so you will have to discard it.
Once the brake pipe is roughly in position, make sure the ends can be connected to the respective points on the vehicle (junctions, flexi-pipes and other pipes). Carefully tighten each connection, making sure it isn’t cross-threaded.
Wash all areas where brake fluid has leaked, especially over paintwork (most types of brake fluid are corrosive on paintwork). Spray brake cleaner over the connections to clean and dry them, then bleed the brakes and check for leaks.